1. Technical Field of the Invention
This invention most generally relates to means for removing ticks and similar parasites from living hosts.
More particularly, it relates to the manual removal from the host of live ticks whose head and jaws are embedded in the host.
2. Background Art
Ticks are members of a group of relatively large blood sucking insects of the order ACARI, and of the families IXODIDAE, ARGASIDAE and HIPPOBOSCIDAE. They are wingless and have a barbed proboscis which extends from the head. The proboscis is inserted into the skin of a warm blooded host for extracting blood, which is stored in the tick's large sac-like abdomen. When it's proboscis and head are firmly embedded in a host's skin, it is not easily removed. Rocky Mountain Spotted Fever and Lyme Disease are two examples of infectious agents which can be transmitted by these parasites.
Ticks have a well defined division between the head and thorax-abdomen. The latter is relatively easy to rend from the former when attempting to remove the tick from the host by twisting or pulling on the tick's plump body with fingers or tools, leaving the head and barbed proboscis inaccessibly embedded in the host. This can lead to further injury and increased likelyhood of infection.
The tick problem has prompted a wide-ranging response over the years. Many new patents have issued even recently, indicating recognition of a continuing problem and room for improvement in the field.
The overall scope of the art is broad, however the differences between individual disclosures are much less dramatic. Some of the art is directed to professionals who can justify more expensive equipment. Some can be seen to be cheaper, simpler, and more readily used by the casual user like parents, pet owners, farmers, and so on.
Among the background art is a small plastic spoon with a V slit in the tip opposite the handle, the slit oriented parallel to the handle, evidently used to engage the tick body in a forward motion and pry or scoop it off the skin with a shoveling or prying motion of the spoon. It makes no provision or suggestion for structure to trap the tick for examination and disposal, or for a more ergonomic grip and hand position for more sensitive manipulation. This device requires an awkward forearm motion or twisting wrist motion to manipulate the device.
There are electrified "zappers" like Johnston's U.S. design Pat. No. D335,166, Apr. 27, 1993, but these devices are unnecessarily heavy, bulky, costly and perhaps intimidating or even painful to use. They likewise make little or no attempt to optimize the shape and grip for the sensitivity of the task.
Eichhorn, U.S. Pat. No. 5,078,729, Jan. 7, 1992, discloses a spring-loaded, normally closed, squeeze clamp where the jaws, when closed, form a cavity of sufficient size to contain the tick's body, with a small opening in the cavity at the extreme end of the closed jaws to prevent the crushing and severing of the tick's body at the point of penetration in the host's skin. The clamp is held in the open position, vertically aligned and positioned over the tick and allowed to close on the tick, enabling the user to then twist or pull to extract the tick from the host. This device utilizes a normally closed clamping action, and obscures the tick from the user's view during the critical extraction process. It requires an inordinate amount of arm and wrist motion to position and operate.
Tweezers and modified tweezers are illustrated by Davidson, U.S. Pat. No. 4,303,268, Dec. 1, 1981. This device may be best described as a bootie on a pair of tweezers. It is simply a retention means to hold a pair of common tweezers in closing tension against a tick's body. The axis of application and operation is straight down on the target, and interferes with the line of sight. There is no provision to prevent inadvertent crushing of the tick, and the operation of such a device is likely to induce excessive forces and movements relative to the necessary delicacy of the extraction process.
Childs, U.S. Pat. No. 4,979,771, Dec. 25, 1990, discloses a normally-open variation of Eichhorn with an electric heater which applies heat to the tick when the device is closed, to induce the tick to let go.
Glaberson, U.S. Pat. No. 4,938,764, Jul. 3, 1990, discloses a simple handle and wire loop with a narrow section; the large opening of the loop positioned over the tick and pulled back to bring the narrow section of the loop around the tick's neck. No moving parts, but it does not fully encircle the tick, and may not hold the tick securely after retraction, or the tick body if severed.
Huffman, U.S. Pat. No. 5,276,306, Jan. 4, 1994, discloses a heated tip and spoon combination, where the user relies on the heat to induce the tick to disengage, and then uses the spoon to scoop up and remove the tick.
Webster, U.S. Pat. No. 5,246,449, Sep. 21, 1993, discloses two prying, lifting, leveraging devices. One is an arm with a forked end that is engaged laterally around the tick's neck, and has a hinged lifting lever that when actuated presses downward against the host's skin to apply a lifting force on the fork and the tick.
The other means illustrated is an addition to a common staple puller, where the outer edge of one jaw of the puller is equipped with a base plate configured with a keyhole slot, the narrowest point still sufficiently wide to pass around the neck of the tick, the central opening large enough to pass the tick's head.
A second plate is attached to the inner, curved edge of the opposing jaw of the staple puller, and is slotted so as at and during the closing of the staple puller, it will engage the tick about the neck and pry the tick upward, pulling the tick's head through the opening in the base plate. The tick's head should pass through the base plate as the tick is extracted.
Butler, U.S. Pat. No. 5,116,347, May 26, 1992, discloses an enhanced, pliers-type of handtool. The handle of the one-handed device is perpendicular to the line of sight. The cavity in operation forms an open bowl, providing a clear view of the tick and the extraction process. The jaws of the pliers have beveled mating edges, as well as mechanical stops to provide the optimal opening for the tick's neck.
The principle advantage of a pliers-type tool is the increased pinching force afforded at the jaws by the leverage of the plier handles. This is not a requirement in this application, and in fact teaches away from the sensitivity required for this task.
A further disadvantage to a pliers type tool for this application is that it requires the back end of the hand, the second, third and forth digits opposing the heel of the hand, to open and close a disporportionate distance compared to the limited travel between the thumb and forefinger and the limited force required for this application. This unnecessary muscle flexure and movement only increases the likelyhood of rending the tick's body from it's head.
It is common knowledge, and expounded in the art, that there is both risk and harm in severing or rendering the tick from it's head during attempts to remove it. Divergent ideas on manual removal of a live tick, intact, are all too readily apparent in the cited art. No solution in the art stands out as significantly better than other known solutions, but small variations have been recognized as patentable.
The actual removal of a live tick being a delicate matter, the most notable shortcoming of the art is a lack of recognition of the ergonomic benefits and improved performance achievable through design innovations that combine the sensitivity available in natural hand placement and thumb and finger movement, with complimentary structure that is a task-specific extension of the user's hand.